[Chrysalis]

The cheapest and most realistic option for you is probably SDSL, the crunch point is ultimately you have to raise your budget. Upstream bandwidth costs more for the isp to provide then downstream bandwidth it is also much more catastrophic if upstream is saturated since it makes downstream plummet to a small slice of its max speed and causes all sorts of latency problems. I dont see anything reasonable in your request for asking for a big upload pipe for under £30 a month it just isnt viable.